Researches on Fuzzy Creep Compensation of Load Cell

Creep is a critical specification of load cell. Based on the analysis of creep, a new compensation technique, fuzzy creep compensation, is presented in this paper. It firstly introduces the fuzzy recognition to determine loading situations. Compared to the other compensation methods, fuzzy creep compensation can avoid the complicated modeling of creep performance, and it is also proved to be an efficient and simple approach to improve the accuracy of load cell by experiments.

Web Tension Regulation of Multispan Roll-to-Roll System using Integrated Active Dancer and Load Cells for Printed Electronics Applications

The mass production of primed electronics can be achieved by roll-to-roll（R2R） printing system, so highly accurate web tension is required that can minimize the register error and keep the thickness and roughness of printed devices in limits. The web tension of a R2R system is regulated by the use of integrated load cells and active dancer system for printed electronics applications using decentralized multi-input-single-output（MISO） regularized variable learning rate backpropagation artificial neural networks. The active dancer system is used before printing system to reduce disturbances in the web tension of process span. The classical PID control result in tension spikes with the change in roll diameter of winder and unwinder rolls. The presence of dancer in R2R system shows that improved web tension control in printing span and the web tension can be enhanced from 3.75 N to 4.75 N. The overshoot of system is less than ±2.5 N and steady state error is within ± 1 N where load cells have a signal noise of ±0.7 N. The integration of load cells and active dancer with self-adapting neural network control provide a solution to the web tension control of multispan roll-to-roll system.

Characteristics of Dynamic Load Response of a Fuel Cell with a Dead-ended Anode

The dynamic load characteristics of a proton exchange membrane fuel cell（PEMFC） with a dead-ended anode were studied. In a 70 h experiment, the effects of anode pressure, operating temperature, and relative humidity of the cathode on the performances of the fuel cell were investigated. The obtained results show that, with different relative humidity of the cathode at 65 ℃, dynamic loading has little effect on the performances of fuel cell and the electrochemically active surface area（ECSA）. However, the fuel cell operating under dynamic load is unstable when the relative humidity is 50%, and at 50 ℃ with 100% relative humidity, applying a dynamic load has a significant influence on the fuel cell performances. Scanning electron microscopy（SEM） showed that both the upstream and middle catalyst layers of the cell were unchanged, whereas the downstream cathode catalyst layer thinned as a response to dynamic load.

Dental pulp stem cells express tendon markers under mechanical loading and are a potential cell source for tissue engineering of tendon-like tissue

Postnatal mesenchymal stem cells have the capacity to differentiate into multiple cell lineages. This study explored the possibility of dental pulp stem cells （DPSCs） for potential application in tendon tissue engineering. The expression of tendon- related markers such as scleraxis, tenascin-C, tenomodulin, eye absent homologue 2, collagens I and VI was detected in dental pulp tissue. Interestingly, under mechanical stimulation, these tendon-related markers were significantly enhanced when DPSCs were seeded in aligned polyglycolic acid （PGA） fibre scaffolds. Furthermore, mature tendon-like tissue was formed after transplantation of DPSC-PGA constructs under mechanical loading conditions in a mouse model. This study demonstrates that DPSCs could be a ootential stem cell source for tissue enEineerin~ of tendon-like tissue.

Nomograms based on HPV load for predicting survival in cervical squamous cell carcinoma: An observational study with a longterm follow-up

Objective: To investigate the prognostic value of pretreatment human papillomavirus(HPV) viral load for cervical cancer, and to develop nomograms based on HPV load and other clinicopathological factors for long-term survival.Methods: We conducted a prospective study on cervical squamous cell carcinoma(SCC) patients diagnosed between January 2003 and December 2008. Cervical samples were tested for HPV viral load by the Hybrid Capture II(HCII) assay before treatment and 6 months after treatment. Clinical characteristics and follow-up information were also collected. A multivariable Cox proportional hazards model was used to adjust covariates in both the radical hysterectomy(RH) treatment group and concurrent chemoradiotherapy(CCRT) treatment group to identify relevant covariates, and then nomograms were constructed and used for internal validation.Results: A total of 520 SCC patients enrolled in this study with a median follow-up of 127 months, 360 patients received RH, whereas 160 patients received CCRT. The median HPV viral load in RH and CCRT groups was356.10 and 294.29, respectively. Tumor size was positively correlated with high pretreatment HPV load in both groups. In CCRT group, the advanced International Federation of Gynecology and Obstetrics(FIGO) stage and enlarged retroperitoneal lymph node status determined by computed tomography(LNSCT) were correlated with low HPV load group. Initial HPV viral load, FIGO stage and lymph node metastasis were prognostic factors for RH group, whereas HPV viral load, squamous cell carcinoma antigen(SCC-Ag) level and LNSCT were identified as prognostic factors for CCRT group. Nomograms incorporating these predictors for 10-year progression-free survival(PFS) were constructed [concordance index(C-index): 0.756, 0.749].Conclusions: A low pretreatment HPV viral load is an independent prognostic factor for poor prognosis of cervical SCC and is related to other clinicopathological factors. The survival nomogram based on HPV viral load could predict the long-term prognosis.

Development and installation of bedload monitoring systems with submerged load cells

Bedload governs riverbed channel variations and morphology, it is necessary to determine bedload discharge through an arbitrary cross section in a mountain fiver. A new system with submerged load cells has been developed to directly measure bedload discharge. The system consists of： （1） an iron box which is 1 m long, 0.5 m wide and 0.1 m in depth, （2） two submerged load cells 0.7 m apart, （3） a pressure sensor and, （4） an electromagnetic velocity meter. This system has been designed to exclude the effect of the hydraulic pressure of water on direct measurements of bedload particle weight. Initial tests in a laboratory were conducted to examine the accuracy of measurements with the system under aerial conditions. The system has been installed in the supercritical flume in Ashi-arai-dani River of the Hodaka Sedimentation Observatory of the Disaster Prevention Research Institute （DPRI） of Kyoto University to obtain bedload discharge under natural conditions. Flume tests were conducted in this channel by artificial supply of uniform sediment particles of several grain sizes. The average velocity of the sediment particles near the bed was estimated using cross-correlation functions for weight waves obtained by the two load cells, Bedload discharge calculations were based on time integration of the product of sediment velocity and sediment weight obtained by the two load cells. This study clarifies the reasons why bedload measurements are difficult, and provides some solutions using the monitoring systems with submerged load cells through the field measurements. Additionally, the applicability of bedload measurement with the submerged load cells is explained based on experimental artificial sediment supply data.

Load Balancing for Hex-Cell Interconnection Network

The hex-cell is one of the interconnection networks used for parallel systems. The main idea of the hex-cell is that there are hexagon cells that construct the network;each one of those cells has six nodes. The performance of the network is affected by many factors one of the factors as load balancing. Until the moment of writing of this paper, there is no load balancing algorithm for this network. The proposed algorithm for dynamic load balancing on hex-cell is based on Tree Walking Algorithm (TWA) for load balancing on tree interconnection network and the ring all to all broadcast.

Mechanical loading of adipose derived stromal cells causes cell alignment

Osteoarthritis is a debilitating disease that affects hundreds of millions of people worldwide. Current research involving growth and characterization of adipose derived stromal cells (ADSC) in vitro offers a potential solution for the treatment of cartilage de-fects that will allow patients to return to the physical activities they were involved in. Studies have shown that fibroblast cells grown in vitro respond to cyclic mechanical stretching by orienting in a direction perpendicular to the direction of stretch. ADSCs were isolated from human peripatellar adipose tissue discards. Cells were cultured until confluent and seeded at a density of approximately 105 cells in silicone wells pretreated with ProNectin-F Plus. After stret-ching, relative alignment of the cells was ascertained using imaging software. Stretching cells for 3, 4, 8 and 12 hours resulted in noticeable cellular alignment of approximately 60? relative to the direction of loading. Cell alignment is crucial for developing tis-sue-engineered cartilage that has similar mechanical properties to native cartilage. Mechanically loading cells is one method to achieve cell alignment. Since cell differentiation will be initiated after alignment, the resulting chondrocytes will be aligned, leading to organized collagen formation and resulting in a hya-line-like cartilage structure.

Load-Measuring Pot Bearing with Built-In Load Cell —Part I: Design and Performance

This paper presents the underlying principle and the results of various performance evaluations for a load-measuring pot bearing with built-in load cell. The pot bearing composed of a pot made of steel in which an elastomer disk is inserted is a bearing supporting larger loads than the elastomeric bearing and accommodating rotational movement. Owing to a Poisson’s ratio close to 0.5, elastomer withstands hydrostatic pressure when confined in a rigid body. Accounting for this principle, the vertical load applied on the pot bearing can be obtained by converting the pressure acting on the elastomer. Therefore, a load-measuring pot bearing is developed in this study by embedding a load cell exhibiting remarkable durability in the base plate of the bearing. The details for the insertion of the load cell in the base plate of the pot were improved through finite element analysis to secure sufficient measurement accuracy. The evaluation of the static performance of the pot bearing applying these improved details verified that the bearing exhibited sufficient accuracy for the intended measurement purpose. The dynamic performance evaluation results indicated that accurate measurement of the dynamic load was also achieved without time lag.

Load-Measuring Pot Bearing with Built-In Load Cell —Part II: Fatigue Performance and Experimental Temperature Correction

This paper presents the results of fatigue performance tests performed up to 10 million cycles on a load-measuring pot bearing with built-in load cell to verify its field applicability and proposes an empirical temperature correction formula. In Part I of this work, various measurement performances of the load-measuring pot bearing were evaluated through static and dynamic loading tests. Bridge bearings are subjected to the effect of fatigue caused by the repeated application of moving loads and exposed to harsh site conditions including cold and hot weathers differently to laboratory conditions. Accordingly, the durability of the load-measuring pot bearing with built-in load cell shall be secured and the environmental effects like temperature shall be minimized for its application on field. This study conducted fatigue tests up to 10 million cycles on a load-measuring pot bearing with the capacity of 1000 kN to examine eventual degradation of the measurement accuracy with respect to the number of fatigue loading cycles. In addition, the experimental temperature correction procedure is proposed to obtain the temperature correction formula enabling to correct the effect of temperature on the load measurement.

A Uniaxial Loading Device for Studying Mechanoresponses of Single Plant Cell

A system which consists of a loading chamber unit, displacement sensor, data collector and processor, and a feedback control, was established for applying mechanical forces to single plant cells. The method works by compressing an agar cell-suspension block between parallel surfaces through using a force-feedback control circuit coupled to a microchip, delivering the pre-defined. The actual controlled stimulus is achieved whilst measuring the force being imposed on the cell, and its deformation. TheArabidopsisprotoplasts were utilized to test the system. It provides an experimental approach to investigate the mechanoresponses of plant cellsin vitroconditions.

活动门试验中土压力盒标定方法

为确保活动门试验结果的准确性,根据试验填土深度的不同,对一批相同型号的电阻式土压力盒进行了垂直方向上的分级加载和卸载标定,并考虑标定装置内壁摩擦力影响,修正了作用在土压力盒上的有效加载和卸载应力。通过对加卸载过程进行离散元模拟,证明有效加载和卸应力修正方法较为合理。标定试验结果表明,加载过程中微应变量-有效应力曲线呈线性变化,可使用线性函数拟合;卸载过程中微应变量-有效应力曲线存在明显的滞后现象,且滞后程度随有效加载应力的增大而增大,可使用单指数曲线拟合。标定土压力盒后,开展了填土试验,结果表明土压力盒不宜在压力过小或填土深度过小时使用。

PRP联合ADSCs负载藻酸钙凝胶修复软骨缺损的效果研究

目的探讨富血小板血浆(PRP)联合脂肪间充质干细胞(ADSCs)负载藻酸钙凝胶修复软骨缺损的效果。方法取新西兰大白兔皮下脂肪分离培养ADSCs,制造兔关节软骨缺损模型,然后将ADSCs种植到负载PRP的藻酸钙凝胶上,构建组织工程软骨并移植到缺损处。实验分为3组:对照组、PRP组和PRP-ADSCs-藻酸钙凝胶组,每组10只。术后观察细胞形态和生长情况,甲苯胺蓝染色和Ⅱ型胶原免疫组化染色等方法检测成软骨特性,CCK-8法检测ADSCs增殖活性,RT-PCR检测Ⅱ型胶原mRNA和蛋白多糖mRNA表达。结果在倒置相差显微镜下,ADSCs呈现典型的间充质干细胞形态,即梭形或椭圆形,细胞质丰富,核形规则。随着培养时间的延长,ADSCs逐渐呈现出良好的生长状态,细胞数量增多,细胞间连接紧密,形态规则。对照组软骨缺损区未见明显修复,染色呈浅蓝,ADSCs数量多;PRP组软骨缺损区部分修复,染色呈蓝色,ADSCs数量较对照组多;PRP-ADSCs-藻酸钙凝胶组软骨缺损区修复效果最好,染色呈深蓝色,ADSCs数量较PRP组多。诱导14 d后,ADSCs甲苯胺蓝异染阳性,胞浆及细胞周围出现紫红色异染。Ⅱ型胶原免疫组化染色显示,PRP-ADSCs-藻酸钙凝胶组ADSCs平均灰度值明显高于其他组(P<0.05);阳性细胞胞浆内可见棕黄色颗粒,细胞周围黄染。CCK-8检测显示,PRP-ADSCs-藻酸钙凝胶组ADSCs第2天进入指数生长,对照组第3天才开始进入指数生长状态。在观察期间内,PRP-ADSCs-藻酸钙凝胶组软骨诱导后ADSCs OD值显著高于其他组(P<0.05)。PRP-ADSCs-藻酸钙凝胶组Ⅱ型胶原mRNA表达明显高于其他组(P<0.05)。3组ADSCs的蛋白多糖mRNA表达随时间增加而递增,第14、21天PRPADSCs-藻酸钙凝胶组ADSCs的蛋白多糖mRNA表达明显高于其他组(P<0.05)。结论利用PRP、ADSCs、藻酸钙凝胶形成的复合体初步构建组织工程软骨对缺损关节软骨进行修复,可提高ADSCs增殖活性及Ⅱ型胶原和蛋白多糖mRNA表达水平,使缺损的关节软骨得到明显修复。

计及热负荷柔性的户用氢能系统运行优化研究

针对风电/光伏出力的随机性和间歇性给户用氢能系统热电联供可靠性带来的挑战,提出基于热负荷柔性松弛运行约束的户用氢能系统热电联供优化策略。首先,搭建包含不同模块的户用氢能系统基础架构,并详细说明该系统的运行原理;其次,建立系统中关键环节的数学模型,确定电解槽平均氢/热比和燃料电池在不同温度下电/热比的范围;然后,为了兼顾用户的舒适度和热负荷的灵活性,根据热感觉平均标度预测指标对户用氢能系统的热负荷需求进行调整;最后,综合考虑储氢罐的容量限制、氢能设备的电/热功率和用户侧柔性热能需求等约束条件,以总投资成本最少和新能源弃电率最低为目标,建立户用氢能系统优化运行模型。仿真结果表明:引入柔性热负荷进行运行调节时,不仅增强了可再生能源的消纳能力,还显著降低了系统的运行成本。

网状孔壁碳化硅基多孔陶瓷的制备及其颗粒物过滤研究

为了提高碳化硅基多孔陶瓷的过滤性能,以碳化硅粉体、氧化铝粉体、聚醚多元醇、多亚甲基多苯基异氰酸酯、二月桂酸二丁基锡、三乙烯二胺、稳泡剂硅油(阿拉丁)为原料,通过聚氨酯发泡技术,研制了三维(3D)网状孔壁结构的碳化硅基多孔陶瓷试样,并探索了料浆固含量(固相质量分数分别为45%、50%、55%和60%)对试样显微结构、物理性能和颗粒物过滤性能的影响。结果表明:1)随着固含量的升高,试样体积密度和常温耐压强度提高,显气孔率降低;2)聚氨酯发泡过程中产生的微孔会分布在陶瓷孔壁上形成网状孔壁结构,增大颗粒物与孔壁碰撞概率,提高试样的过滤效率;同时,网状孔壁结构还可以提高试样气孔贯通性,降低其压降;3)当固含量为55%(w)时,试样体积密度约为0.57 g·cm^(-3),显气孔率为79.2%,常温耐压强度为3.7 MPa;且对颗粒物的去除率高达91.2%,具有良好的再生性能。

不同病毒载量的乙型肝炎病毒在不同ALT状态下对肝星状细胞增殖、细胞周期及细胞分泌的影响

【目的】临床上经常以ALT是否正常等因素将乙型肝炎感染者分为乙型肝炎携带者或乙型肝炎患者,并且以ALT≥2UNL作为临床抗病毒治疗的适应症之一,但是目前尚缺乏足够的文献阐明其理论学依据,本文借助乙型肝炎病毒对肝星状细胞的影响对此进行探讨。【方法】分层随机选取不同ALT状态下不同病毒载量的慢性乙型肝炎的患者132例,作为干扰血清。经干扰血清干预HSC后,分别用MTT法检测HSC增殖,流式细胞仪检测HSC细胞周期,RT-PCR和免疫印迹分别检测TGF-β1、Smad3、Smad7、α-SMA、collagenⅠ、collagenⅢmRNA及蛋白的表达,同时对ALT≥2UNL的慢性乙肝患者抗病毒治疗随访24周,对比分析治疗前后患者干扰血清对肝星状细胞的影响。【结果】在ALT正常状态下,不同病毒载量的乙型肝炎病毒对肝星状细胞增殖、细胞周期及细胞分泌无差别性影响。而在ALT异常状态下,特别是ALT≥2UNL组中,随着病毒载量的增加,HSC增殖加速,处于G0/G1期的明显减少,而处于S期,G2/M期的明显增多以及TGF-β1、Smad3、CollagenⅠ、CollagenⅢ、α-SMA mRNA及相应蛋白的表达明显增高,Smad7 mRNA及蛋白明显减少,差异有统计学意义。与抗病毒治疗前相比抗病毒治疗后,干扰血清对肝星状细胞的影响明显减弱。【结论】本文揭示了在不同ALT状态下乙型肝炎病毒对HSC的差异性影响,并通过抗病毒治疗前后对比分析。补充说明了以ALT为节点抗病毒治疗乙型肝炎病毒的细胞学理论基础。

Higher Viral Load and Prolonged Viral Shedding Period is Associated with Impaired Th17 Cell Response in Patients with H1N1 Influenza A

Objective To explore whether age,disease severity,cytokines and lymphocytes in H1N1 influenza A patients correlate with viral load and clearance.Methods Total of 70 mild and 16 severe patients infected with H1N1 influenza A virus were enrolled in this study.Results It was found that the patients under 14 years old and severe patients displayed significantly higher viral loads and prolonged viral shedding periods compared with the patients over 14 years old and mild patients,respectively(P < 0.05).Moreover,the patients under 14 years old and severe patients displayed significantly lower Th17 cell frequency than the patients over 14 years old and mild patients(P < 0.01).The viral shedding period inversely correlated with the frequency of IL-17+IFN-γ-CD4+ T cells.Additionally,the decreased concentration of serum TGF-β correlated with the decreased frequency of IL-17+IFN-γ-CD4+ T cells.Conclusions Both younger and severe patients are associated with higher viral loads and longer viral shedding periods,which may partially be attributed to the impaired Th17 cell response.

燃料电池氢气流量控制系统变负载匹配设计与仿真

针对车载质子交换膜燃料电池供氢系统负载工况多变时的氢气流量控制问题,提出一种基于比例减压阀与流量控制阀的氢气流量负载匹配控制系统架构与方法。建立了从高压储氢瓶至燃料电池堆的供氢系统整体模型,基于该模型设计了比例减压阀、流量控制阀与氢气循环泵的控制策略,并就某一型号电堆的变负载工况对系统模型与控制策略进行仿真验证。结果表明:电堆阳极压力可快速跟踪给定压力,响应时间约2~3s;氢气流量可适应负载变化需求,其瞬时超调量与压力响应速度成正相关;稳态时氢气利用率维持在95%以上,供氢过量比维持在1.27以上,供气氮含量维持在5%以下,满足电堆性能需求。

基于节点网元的韧性配电网时-空调度序列协同优化负荷恢复策略

为提升配电网的韧性,在更大的时间尺度和空间范围内确保新型电力系统下灵活、高效的电力供应,提出一种新颖的基于节点网元的韧性配电网时-空调度序列协同优化负荷恢复策略,获取配电网灾后场景下的最优负荷恢复序列方案及其调度时刻表。在多智能体代理系统架构下提出节点网元的概念,制定负荷恢复序列方案,通过邻近节点间局部信息的交互获取全局参数信息,作为灾后信息网络受损下负荷恢复优化模型的输入。对灾后负荷恢复模型中的混合整数线性规划问题进行求解,获取负荷恢复路径及修复时刻表,形成由多个分布式电源组成的节点网元以恢复停电负荷,实现检修人员调度和操作人员调度间的协同优化。最后,通过改进IEEE 37节点和IEEE 123节点系统验证了所提协同调度优化模型的有效性。

不同产地叶蜡石的传压特性

作为密封传压介质,叶蜡石已被广泛应用于实验室和工业的高压合成中。然而,叶蜡石中矿物成分的改变将影响其传压效率及密封性。本研究中在6×8 MN大腔体六面顶压机中完成4种不同产地叶蜡石在室温下的压力标定工作,并通过X射线衍射研究叶蜡石中矿物组成的变化对传压效率的影响。结果表明:叶蜡石中含有较高硬度的矿物(如水铝石、勃姆石、白云母和高岭石),可有效提升叶蜡石的传压效率;随着腔体压力提升,叶蜡石的传压效率逐渐降低,施加更高的实际加载力(油压)也不能明显地提高腔体压力;高压处理后的叶蜡石4比叶蜡石2有更好的传压效率,但受矿物成分变化的影响,叶蜡石4容易发生密封失效,而叶蜡石2有良好的弹性回复效果和密封性,能够稳定完成升压卸压过程。综合考虑传压效率和密封效果,叶蜡石2具有最佳的应用价值和经济效益。